Cam stop improvement

ABSTRACT

An improvement in a fiber-blending system of the type whereby a plurality of weighing pans are disposed above a conveyor belt and are fed with fiber material, which is dumped onto the conveyor periodically after all of the pans have weighed a chosen amount. The conveyor onto which the fibers are dumped is normally caused to move forward after each dump for a given distance so that fiber sandwiches are formed on the conveyor to be delivered to other equipment. Normally connected in parallel with a relay energizing the conveyor for forward movement is a spraying relay which, when energized, causes a tint, dye or the like to be sprayed onto the fibers as they move with the conveyor so that the spraying relay is energized to spray a different sandwich each time that the conveyor moves forward. In the prior art circuit for controlling the operation of the equipment as described herein, the conveyor is normally energized briefly after the fibers in the pan are dumped to ensure that a switch, which is closed to stop the conveyor, is open, and then deenergized briefly before being once more energized to move forward the rest of the given distance. This double energization of the conveyor relay, and hence the spray relay, causes the fiber sandwiches to be sprayed twice for each dump rather than once as desired. The improvement of this invention, as disclosed below, overcomes this problem by providing a circuitry so that the conveyor relay, and hence the sprayer relay, is only energized once for each dump of the weigh pans.

[72] Inventors Dans. Wise;

James 1L. Sosebee, both of Gastonin, NC.

, 21 Appl. No. 846,130

[22] Filed July 30, 11969 [45] Patented Dec. M, 19711 2 [73] Assignee Fiber Controls Corporation Gastonia, NC.

1 [54] CAM STOP IMPROVEMENT Iii Claims, 11 Drawing Fig.

Primary Examiner-Robert W. Jenkins Arl0rney-Cushman, Darby & Cushman ABSTRACT: An improvement in a fiber-blending system of the type whereby a plurality of weighing pans are disposed above a conveyor belt and are fed with fiber material, which is dumped onto the conveyor periodically after all of the pans have weighed a chosen amount. The conveyor onto which the fibers are dumped is normally caused to move forward after each dump for a given distance so that fiber sandwiches are formed on the conveyor to be delivered to other equipment. Normally connected in parallel with a relay energizing the conveyor for forward movement is a spraying relay which, when energized, causes a tint, dye or the like to be sprayed onto the fibers as they move with the conveyor so that the spraying relay is energized to spray a different sandwich each time that the conveyor moves forward, in the prior art circuit for controlling the operation of the equipment as described herein, the conveyor is normally energized briefly after the fibers in the pan are dumped to ensure that a switch, which is closed to stop'the conveyor, is open, and then deenergized briefly before being once more energized to move forward the rest of the given distance. This double energization of the conveyor relay, and hence the spray relay, causes the fiber sandwiches to be sprayed twice for each dump rather than once as desired. The improvement of this invention, as disclosed below, overcomes this problem by providing a circuitry so that the conveyor relay, and hence the sprayer relay, is only energized once for each dump of the weigh pans.

CAM STOP IMPROVEMENT BRIEF DESCRIPTION OF THE PRIOR ART AND SUMMARY OF THE INVENTION The invention relates to an improvement in fiber-blending equipment whereby the conveyor relay which causes the conveyor to move forward after each dump of the weigh pans onto the conveyor, and the sprayer relay connected in parallel with it are only energized once for each dump of the weigh pans.

The textile industry is quite familiar with automatic-blending line equipment of the type which forms a continuous chain of fiber sandwiches on a moving conveyor such as disclosed and claimed in the Lytton et al. U.S. Pat. No. Re. 25,609 and the Wise et al. U.S. Pat. No. 3,325,848. Such equipment has been used for many years to sandwich-blend various types of textile fibers, both synthetic and natural. Many times, if not most of the time, different bales of fibers, whether they are natural or synthetic. need to be mixed by such blending equipment in order to give them uniformity. Most synthetic fiber manufacturers and dealers of natural fibers recommend mixing different bales of the same type of fibers, since greater uniformity in the product can thereby be obtained. Generally speaking, sandwich blending is preferred to prevent streaks in the yarn or fabric manufactured from the sandwiches.

The method and apparatus disclosed in the above-mentioned Lytton and Wise patents for effecting such automatic blending employs a number of feeders along and above a single conveyor belt or line. Each type of material to be blended is fed into one of the weigh pans where it is weighed and the flow cut off when the desired amount has been received therein. When all the weigh pans have received the necessary material for any given blend and weigh the correct amount, the pans are simultaneously dumped onto the conveyor belt which then moves forward a short distance and halts until the next dump so as to build up the proper sandwiches on the conveyor. At the same time, the pans are refilled and then once again dumped when all have received the proper amount of material. Appropriate electrical circuitry, such as disclosed in the above-mentioned Lytton and Wise patents, normally controls the feeding and cutting-off of the fiber material into the weigh pans, dumping the material onto the conveyor at the proper time and stopping and starting the conveyor after dumping.

Also, it is conventional to spray liquid, such as tint or dye, onto the sandwiches as they move along the conveyor to equipment which then uses or processes the fiber sandwiches. Sprayers capable of spraying a mist of droplets onto the sandwiches on the conveyor are well known and are usually operated by a sprayer relay which is activated to cause spraying by the flow of electrical current through it. Further, this sprayer relay is normally and conveniently connected in parallel with a conveyor relay which is similarly activated to cause the conveyor to move forward. Thus, each time that the conveyor relay is energized, which normally occurs after each dump, it causes the conveyor to move forward a given distance before stopping to await the next dump, and at the same time a sandwich is sprayed by the sprayer unit.

However, the control circuitry now used to control the feeding and dumping of material and to cause the conveyor relay to be energized after each dump to move the conveyor forward is constructed so that, after the dump, the conveyor relay is momentarily energized to cause the conveyor to move a short distance and is then deenergized, stopping the conveyor. Immediately thereafter, it is reenergized and the conveyor belt moves again until it has travelled the total distance required for proper sandwich buildup at which time the conveyor relay is deactivated.

The reason for this double activation is that a cam dump switch is normally associated with a cam on a timing chain associated with the conveyor. When the cam jump switch is closed by the cam, then the conveyor has moved far enough and the control circuitry deactivates the conveyor relay until the end of the dump. However, to ensure correct operation, it is necessary to make sure that the cam dump switch has reopened by the end of the dump. This was accomplished by the short energization of the conveyor relay during the dump.

This double activation of the conveyor relay causes no sub stantial problem as far as movement of the conveyor itself is concerned, but, since the sprayer relay is connected in parallel with the conveyor relay, it is also energized twice and this causes double spraying of each sandwich with resultant waste of the spray as well as potential other problems resulting from an overabundance of the sprayed material on the fiber sandwich. Further, the sprayer is operated twice as frequently as necessary.

The present invention relates to an improvement in the control circuitry as described below which causes the conveyor relay, and accordingly the spray relay mounted in parallel with it, to be energized after the end of each dump and to remain energized until the conveyor has moved completely to the desired position. This is accomplished by causing the conveyor to move past the point closing the cam dump switch before stopping so that the switch is already open at the beginning of the dump. Thus, the conveyor relay can remain deactivated until the dump is completed. Accordingly, the sprayer unit only sprays each fiber sandwich once for each movement of the conveyorand for each dump of the system.

Many other objects and purposes of the invention will be clear from the following detailed description of the drawing.

BRIEF DESCRIPTION OF THE DRAWING The FIGURE shows control circuitry for fiber-blending equipment whereby the conveyor relay and the sprayer relay connected in parallel with it are energized only once for each forward movement of the conveyor and for each dump of the weigh pans.

DETAILED DESCRIPTION OF THE DRAWINGS Reference is now made to the FIGURE which shows control circuitry suitable for controlling the feeding, weighing and dumping of fiber material in a fiber-blending system of the type described briefly above and in detail in the above-mentioned Lytton and Wise patents. The: circuitry is also very similar to the control circuitry illustrated in Wise, U.S. Pat. No. 3,439,838 and the disclosure of all those patents is explicitly incorporated herein by reference. The operation of the control circuitry shown in the FIGURE should be apparent from the disclosure of these patents and particularly from the Wise Patent, U.S. Pat. No. 3,439,838.

As mentioned briefly above, the circuit shown in the FIGURE controls the feeding of fiber material into the plurality of associated weigh pans of which three-W W and W;,--- are diagrammatically illustrated in the FIGURE. Selector switches SW,, SW, and SW; are also provided to permit operation with less of all of the weigh pans by shifting the selector switch associated with each unused weigh pan away from its illustrated position, and these selector switches are further discussed in the abovementioned Wise patent, U.S. Pat. No. 3,439,838. Feeding of material into each weigh pan is normally accomplished by means of suitable electric motors and three such feed motors FM FM and Flt/l are also diagrammatically illustrated in the FIGURE. Assuming that the switch L8,, which is labeled PS in the Lytton et al. patent U.S. Pat. No. 25,609, is closed indicating a demand for fiber sandwiches as discussed in greater detail below, the operation of the circuitry of the FIGURE will now be briefly described.

After the three weigh pans W,, W, and W have simultaneously dumped material onto the conveyor 6, which is not shown in the FIGURE but which is fully disclosed and discussed in the above-mentioned Lytton et al. and Wise patents, an electrical current path is completed through the conveyor relay CV which then operates a switch (not shown) causing the conveyor 6 to move forward by supplying power to a suitable conveyor motor. As mentioned above, a sprayer relay SP is connected in parallel with relay CV so that a sandwich is sprayed each time relay CV is activated. This path runs from the alternating current source 8 through an on-off switch 10 down lines 12 and 68, through switch SD, (which is in the illustrated position), down line 70, through the picker or limit control switch labeled LS, down line 72 to contact C, through switch TD, (which is nonnally in the position shown), down line 92, through SD, to contact A, and down line 96, 122, through the start switch, relay CV and lines 124, 16 and 14 to the other side of the alternating current sourcev8. The conveyor 6 then moves forward until the ganged cam dump switches 60 and 61 engage a cam member or other structure mounted on or with the conveyor belt for movement therewith, forcing the switches 60 and 61 to close in a manner, for example, described fully in the above-mentioned Lytton et al. and Wise patents. The closing of switch 60 completes a current path through the relay SD vialine 58, switch 60, line 62, diode 64 and lines 66, 67, 16 and 14. Relay SD then responds immediately to the current flowing through it by shifting controlled switch SD, into connection with line 71, thus cutting ofi' one current path through relay CV. However, switch 61,

which is also closed at the same time as switch 60, maintains relay CV activated until the conveyor 6 moves far enough to open ganged switches 60 and 61. Since switches 60 and 61 are thus always open at the end of the dump, there is no necessity for reactivating relay CV in the middle of the dump as in previous circuits.

The activation of relay SD also closes switches SD, and SD, in preparation for the dump which occurs after all weigh pans are full. A latching circuit for relay SD is also completed by the closing of switch SD, so that relay SD remains activated after switches 60 and 61 open. This latching path runs from line 68 through switch 5D,, lines 71 and 73, normally open but now closed switch DlL,, line 74, diode 64 and lines 66, 67, 16 and 14.

While the conveyor 6 is moving forward, fibers are fed into the weighing pans W,, W, and W, by feed motors FM,, FM, and FM, which are connected to a three-phase source as shown by ganged, normally open switches 40, 42 and 44 which are kept closed by activated relays M,, M, and M,, respectively, which also control normally open switches 46, 48 and 50, respectively. Relays M,, M, and M, are activated as shown by a current path which runs through a closed switch 20, which is a safety switch, line 18 lines 22 and 24, weigh switches WS,, WS, and WS, (which each remain connected to the empty contact E until the weigh pan with which it is associated has weighed the correct amount), line 32, switch TD, and lines 16 and 14.

As each of the weigh pans weighs the correct amount and shifts its WS switch to the F or full contact, the M relay associated with that weigh pan is deactivated and the switches that the M relay controls are returned to their normal positions. Relays TV,, TV, and TV, are connected in parallel with relays M M, and M, and operate trapdoors which prevent the feeding of material into the weigh pans during dumping as discussed in detail in the above-mentioned Lytton and Wise patents. For example, when the weigh pan W, has weighed the correct amount of fibers, switch WS, shifts into connection with contact F and line 80, and relay M, is deactivated, thus opening the switches 40 and 46 which it controls, deactivating feed motor FM and thus cutting off the feeding of fibers into weigh pan W I When all the relays M,, M, and M, have been deactivated, switches 46, 48 and 50 will all be open and normally activated relay DlL will then be deactivated, allowing normally closed switch DlL, to close and thus complete a current path through the timedelay relay TD via line 75, now closed switch 5D,, line 76, normally closed switch DlL,, diode 77, line 78 and lines 16 and 14. The activation of time relay TD shifts the switch TD, into connection with contact D and line 71 but does not recomplete a current path through the conveyor relay CV because switch SD, remains in connection with line 92. However, the shifting of switch TD, does complete a current path via switch SD, through all the dump valve relays DV,, DV, and ov which respond by dumping the contents of each of the weigh pans W,, W, and W, onto the conveyor belt. Normally closed switch TD, is opened and normally open switch TD, is closed by the activation of relay TD with switch TD, completing a latching circuit around the switches DlL, and SD 3 which continues as long as any of the weigh pan switches WS,, WS, and WS, remain connected to an F contact indicating the dump has not been completed. The opening of switch TD, prevents relay D. from being reactivated until relay TD is deactivated.

The deactivation of relay DlL opens normally open switch DIL, thus cutting off the current flow through relay SD which, however, delays a short time before changing the positions of i the switches it controls. After that short period has elapsed,

switch SD, shifts, thus deactivating relays DV,, DV, and DV, and causing the weigh pans to resume their normal state in preparation for receiving a fresh load of material. Likewise, as the now-empty weigh pans move back into connection with the E contacts, the relays M,, M, and M,, TV,, TV, and TV, and DIL are prepared to be reactivated as soon as switch TD, is reclosed by the deactivation of relay TD.

If it were not for the switch 8D,, which remains in contact with line 92 as long as relay SD remains energized, relay CV would be energized for the time that both relays SD and TD are energized. This was previously necessary to make sure that switch 60 was reopened by the end ofthe dump. As mentioned briefly above, the addition of switch 61 eliminates the necessity for this double energization and accordingly switch SD, is employed to prevent it.

After all the weigh switches W,, W, and W, have shifted into connection with an F contact, the flow of current through relay TD is tenninated. However, like relay SD, the relay TD delays a short time, after current through it ceases, before permitting the switches controlled by it to return to their normal positions. One purpose of this delay is to ensure that bouncing of the weigh pans has completely ceased before proceeding to refill the pans. Thus, a short time after the relay SD is deactivated, opening switch 5D,, and all the weigh pan switches WS,, WS, and WS, return to their illustrated positions, the relay TD permits all of the switches controlled by it to resume their illustrated positions, thus reactivating relay DlL, relays M,, M, and M, and relays TV,, TV, and TV,,. The movement of switch TD, back into connection with contact C and line 72 also allows the current to resume flowing through the relays CV and SP so that the conveyor moves forward again until cam dump switches 60 and 61 are again reclosed to activate relay SD and repeat the cycle, and so that relay SP causes a sandwich to be sprayed with suitable liquid material.

The fiber-blending equipment shown in the FIGURE is frequently capable of operating at a greater rate of speed than other equipment down the line receiving the fiber sandwiches formed on the conveyor. Accordingly, provision is made in the circuitry of the FIGURE to stop the fiber-blending equipment automatically if at any time the blending equipment down the line indicates an inability to handle further material. This indication is conveyed to the control circuitry of the FIGURE by switch LS which is disclosed in detail in the above-mentioned Lytton and Wise patents and which is opened when it is desired to stop the blending equipment from dumping further material on the conveyor and to stop the conveyor from moving further.

Many changes and modifications of the circuitry shown in the FIGURE for preventing the double energization of the spray coil and resultant waste of sprayed material should be apparent to anyone of ordinary skill in the art. Accordingly, the scope of the invention is intended to be limited only by the scope of the appended claims.

What is claimed is:

1. Control circuitry for a fiber-blending system comprising:

means for causing fiber material to be fed into each of a plurality of weigh pans,

means for causing the feeding of material into each weigh panto be cut off when that pan has a chosen weight of material therein,

first relay means for causing a conveyor to move forward when said first relay means is activated by a current path through said first relay means,

first switch means associated with said conveyor and adapted to be closed after said conveyor has moved a given distance, 7

second relay means activated by the closing of said first switch means for interrupting said current path,

second switch means ganged for movement with said first switch means and closed with said first switch means so as to create a second current path through said first relay means and thus maintain said first relay means activated until said first and second switch means have been reopened by the movement ofsaid conveyor, and

means for causing said pans to dump said weigh pans onto said conveyor after all said pans have said chosen weight of material therein.

2. A system as in claim I further including third switch means operated by said second relay means for preventing said first relay means from being activated after said first and second switch means are reopened until said second relay means is deactivated and means for deactivating said second relay means after the dump is completed.

3. A system as in claim 2 including a dump valve relay associated with each such weigh pan for causing the material in said pans to be dumped onto said conveyor when said valve relay is activated and wherein said third switch means causes said valve relays to be activated when said second relay means is activated and all of said pans have the chosen weight of material therein.

4. A system as in claim 3 further including fourth switch means associated with each of said weigh pans for indicating when that pan has said chosen weight of material therein. third relay means, activated when all of said fourth switch means indicate that all of said pans have said chosen weight therein, for cutting off the current flow through said second relay means when said third relay means is activated and means for keeping said third relay means activated so long as any of said fourth switch means indicate one of said pans still has said chosen weight therein.

5. A system as in claim 4 wherein said second relay means delays a given time in deactivating after said third relay means cuts off the flow of current through said second relay means and said dump valve relays are activated during said given time.

6. A system as in claim 1 including cam means associated with said conveyor for movement therewith and for causing said first and second switches to be closed after said conveyor has moved said given distance.

7. A system as in claim 1 including sprayer relay means mounted in parallel with said first relay means for spraying liquid on said material on said conveyor whenever said first relay is activated.

iii. in a fiber-blending system of the type wherein fiber material is fed into a plurality of weigh pans, which each accumulate a desired weight of material, the weigh pans are dumped onto a conveyor after all have weighed the chosen weight, a conveyor relay is activated to cause the conveyor to move forward a given distance after each dump so as to build up fiber sandwiches on said conveyor, the position of a cam dump switch is shifted by a cam associated with said conveyor after said conveyor relay, and a sprayer relay is connected in parallel with said conveyor relay so as to cause a sandwich to be sprayed with a liquid material each time said conveyor relay is activated, the improvement comprising a second switch ganged with said cam dump switch so as to keep said conveyor relay activated after the position of said cam dump switch is shifted until both said cam dump switch and said second switch have returned to their initial positions.

9. A method of controlling the blending of fibers comprising the steps of: v

feeding fiber material into each of a plurality of weigh pans,

cutting off the feeding of material into a weigh pan when that pan has a chosen weight of material therein,

dumping said material in said pans onto a conveyor after all of said pans have said chosen weight therein,

activating first relay means by completing a current path through said first relay means to cause said conveyor to move forward after each said dump until a first and second ganged switch are both closed by a cam member associated with said conveyor,

activating second relay means when said first switch is closed to interrupt said current path, and

maintaining said first relay means activated by a second current path completed by said second switch means until said conveyor has moved far enough to reopen said first and second switches.

10. A method as in claim 9 including the step ofspraying the material on said conveyor whenever said first relay is activated.

iii. A method as in claim 10 including the step of preventing said first relay from being reactivated after said first and second switches are reopened until said second relay means is deactivated. 

1. Control circuitry for a fiber-blending system comprising: means for causing fiber material to be fed into each of a plurality of weigh pans, means for causing the feeding of material into each weigh pan to be cut off when that pan has a chosen weight of material therein, first relay means for causing a conveyor to move forward when said first relay means is activated by a current path through said first relay means, first switch means associated with said conveyor and adapted to be closed after said conveyor has moved a given distance, second relay means activated by thE closing of said first switch means for interrupting said current path, second switch means ganged for movement with said first switch means and closed with said first switch means so as to create a second current path through said first relay means and thus maintain said first relay means activated until said first and second switch means have been reopened by the movement of said conveyor, and means for causing said pans to dump said weigh pans onto said conveyor after all said pans have said chosen weight of material therein.
 2. A system as in claim 1 further including third switch means operated by said second relay means for preventing said first relay means from being activated after said first and second switch means are reopened until said second relay means is deactivated and means for deactivating said second relay means after the dump is completed.
 3. A system as in claim 2 including a dump valve relay associated with each such weigh pan for causing the material in said pans to be dumped onto said conveyor when said valve relay is activated and wherein said third switch means causes said valve relays to be activated when said second relay means is activated and all of said pans have the chosen weight of material therein.
 4. A system as in claim 3 further including fourth switch means associated with each of said weigh pans for indicating when that pan has said chosen weight of material therein, third relay means, activated when all of said fourth switch means indicate that all of said pans have said chosen weight therein, for cutting off the current flow through said second relay means when said third relay means is activated and means for keeping said third relay means activated so long as any of said fourth switch means indicate one of said pans still has said chosen weight therein.
 5. A system as in claim 4 wherein said second relay means delays a given time in deactivating after said third relay means cuts off the flow of current through said second relay means and said dump valve relays are activated during said given time.
 6. A system as in claim 1 including cam means associated with said conveyor for movement therewith and for causing said first and second switches to be closed after said conveyor has moved said given distance.
 7. A system as in claim 1 including sprayer relay means mounted in parallel with said first relay means for spraying liquid on said material on said conveyor whenever said first relay is activated.
 8. In a fiber-blending system of the type wherein fiber material is fed into a plurality of weigh pans, which each accumulate a desired weight of material, the weigh pans are dumped onto a conveyor after all have weighed the chosen weight, a conveyor relay is activated to cause the conveyor to move forward a given distance after each dump so as to build up fiber sandwiches on said conveyor, the position of a cam dump switch is shifted by a cam associated with said conveyor after said conveyor has moved said given distance to deactivate said conveyor relay, and a sprayer relay is connected in parallel with said conveyor relay so as to cause a sandwich to be sprayed with a liquid material each time said conveyor relay is activated, the improvement comprising a second switch ganged with said cam dump switch so as to keep said conveyor relay activated after the position of said cam dump switch is shifted until both said cam dump switch and said second switch have returned to their initial positions.
 9. A method of controlling the blending of fibers comprising the steps of: feeding fiber material into each of a plurality of weigh pans, cutting off the feeding of material into a weigh pan when that pan has a chosen weight of material therein, dumping said material in said pans onto a conveyor after all of said pans have said chosen weight therein, activating first relay means by completing a current path through said first relay means to cause said conveyor to move forward after each said duMp until a first and second ganged switch are both closed by a cam member associated with said conveyor, activating second relay means when said first switch is closed to interrupt said current path, and maintaining said first relay means activated by a second current path completed by said second switch means until said conveyor has moved far enough to reopen said first and second switches.
 10. A method as in claim 9 including the step of spraying the material on said conveyor whenever said first relay is activated.
 11. A method as in claim 10 including the step of preventing said first relay from being reactivated after said first and second switches are reopened until said second relay means is deactivated. 